Evaluation of aircrew candidate blood testing.

BACKGROUND: The medical assessment of Royal Air Force (RAF) aircrew candidates includes the measurement of 39 individual blood parameters, grouped into 9 blood test panels, to detect disqualifying medical condition(s) (DMC). Although this program has run for over 20 yr, its contribution to the assessment of fitness to fly remains unquantified. METHODS: To determine whether blood testing independently identified DMC, the medical records of 589 male and female aircrew candidates, assessed at the RAF Officer and Aircrew Selection Centre during 2009 and 2010, were scrutinized for DMC while blinded to blood results. DMC identified through blood testing were then recorded and the sensitivity, specificity, and predictive values were calculated. The costs for the financial year 2009-2010 were estimated. RESULTS: For all candidates ages < or = 32 yr, specificity and positive predictive value for all blood test panels combined were 79% and < 1%, respectively. There were 8 DMC identified by blood testing while 994 (21%) of all panels contained an abnormality. For older candidates, three DMC were detected through blood testing that were not recorded elsewhere. The direct cost of the program, based on monetary charges levied for blood testing, was over pound 10,900 (c. US$16,350) but the total costs, including indirect costs to the RAF and individuals, were considerably higher. CONCLUSION: Blood testing at the initial medical assessment identified few DMC, but the organizational and individual burden associated with the program was substantial. Consideration should be given to the curtailment of blood testing in RAF aircrew candidates.

Survey of spatial disorientation in military pilots and navigators.

BACKGROUND: The direction of future spatial disorientation (SD) research and training is shaped primarily by the outcome of formal investigation of aircraft accidents and incidents. However, another source of vital information is aircrews' experience of SD that does not result in reported incidents. METHODS: A short postal SD survey was distributed to 5 Naval Air Squadrons, 22 Joint Helicopter Command Units, and 7 Royal Air Force stations in the United Kingdom. There were 752 questionnaires, including responses from 562 pilots and 149 navigators, that were returned. RESULTS: Analysis was conducted primarily on the pilot data. The most frequently experienced SD episodes were "the leans" (by 92% of respondents), loss of horizon due to atmospheric conditions (82%), misleading altitude cues (79%), sloping horizon (75%), and SD arising from distraction (66%). In general, the frequency of SD episodes and ratings of severity of the worst ever SD episode were positively related to flying experience (p < 0.05). Overall, pilots who had received in-flight SD training reported more episodes of SD than those who had not participated in this training (p < 0.05). Differences in types of SD experienced were found between aircraft categories, e.g., more episodes of SD during night vision goggle use were reported by rotary-wing pilots compared with fast-jet aviators (p < 0.05). CONCLUSIONS: This preliminary survey has shown that SD is still a significant hazard of military flying. Overall, this study shows that the postal questionnaire is a useful tool for assessing how SD training and experience may benefit the recognition of situations that may cause SD. However, it is difficult to access those situations where aircrew were truly disorientated.